Dentistry

Social isolation among older adults linked to having fewer teeth

Older adults who are socially isolated are more likely to have missing teeth—and to lose their teeth more quickly over time—than those with more social interaction, according to a new study of Chinese older adults led ...

Dentistry

Mystery of children's 'chalky teeth' explained

One in five children have chalky tooth enamel—visible as discolored enamel spots—which often causes severe toothache and decay, and sometimes leads to abscesses, extractions and orthodontic problems.

Other

Doctors find tooth growing inside a patient's nose

A 38-year-old male patient complaining of difficulty breathing through one of his nostrils for several years was found to have an ectopic tooth growing in his nose. In their paper published in The New England Journal of Medicine ...

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Tooth

Teeth (singular tooth) are small whitish structures found in the jaws (or mouths) of many vertebrates that are used to tear, scrape, and chew food. Some animals, particularly carnivores, also use teeth for hunting or defense. The roots of teeth are covered by gums. Teeth are not made of bone, but rather of tissues of varying density and hardness.

Teeth are among the most distinctive (and long-lasting) features of mammal species. Paleontologists use teeth to identify fossil species and determine their relationships. The shape of the animal's teeth are related to its diet. For example, plant matter is hard to digest, so herbivores have many molars for chewing. Carnivores, on the other hand, need canines to kill prey and to tear meat.

Mammals are diphyodont, meaning that they develop two sets of teeth. In humans, the first set (the "baby," "milk," "primary" or "deciduous" set) normally starts to appear at about six months of age, although some babies are born with one or more visible teeth, known as neonatal teeth. Normal tooth eruption at about six months is known as teething and can be painful.

Some animals develop only one set of teeth (monophyodont) while others develop many sets (polyphyodont). Sharks, for example, grow a new set of teeth every two weeks to replace worn teeth. Rodent incisors grow and wear away continually through gnawing, maintaining relatively constant length. Many rodents such as voles (but not mice) and guinea pigs, as well as rabbits, have continuously growing molars in addition to incisors.

This text uses material from Wikipedia, licensed under CC BY-SA